Protocols - rules that ensure the orderly and accurate transmission and reception of data; start and end transmission, recognize error, sent data at the appropriate speed, and identify the correct senders and recipients Handshaking - protocols helps help network devices negotiate and establish communications Packets - the process by which you send a file or an e-mail over a network,the file is actually broken up into small pieces. It is a "parcel" of dad that is sent across a computer network Packet Switching - the technology of dividing a message into several packets that can be routed or independently to their destination to avoid out-of-service or congested links Circuit Switching - establishes a dedicated, private link between one telephone and another for the duration of a call; more efficient alternative to circuit switching TCP/IP (Transmission Control Protocol/Internet Protocol) - breaks messages into packets and addresses them for the transmission over the Internet HTTP (Hypertext Transfer Protocol) - Exchanges information over the web FTP (File Transfer Protocol) - Transfers files between local and remote host computers POP (Post Office Protocol) - Transfers mail from an e-mail server to a client inbox SMTP (Simple Mail Transfer Protocol) - transfers e-mail messages from client computers to an e-mail server IMAP (Internet Mail Access Protocol) - an alternative to POP TELNET (Telecommunications Network) - allows users who are logged on to one host to access another host SSL (Secure Sockets Layer) - Provides secure data transfer over the Internet Ethernet - broadcasts data packets to all networks is accepted only by the device to which it is addressed CSMA/CD Protocol (Carrier Senese Multiple Access with Collision Detection) - takes care of situation in which two network devices attempt to transmit packets at the same time Uplink Port - simple step up from a basic single-humb network is to connect several hubs Wi-Fi Network - transmits data as radio waves over predefined frequencies, much like cordless phones. War Driving/LAN-Jacking - occurs when hackers cruise around with a Wi-Fi equipped notebook computer that is set up to search for Wi-Fi signals coming from home or corporate Wi-Fi networks. War drivers can access and use unsecured Wi-Fi networks WEP (Wired Equivalent Privacy) - essential step in making Wi-Fi-transmitted data useless to intruders Wi-Fi card - transmitter, receiver, and antenna to transmit signals Wireless Access Point - provides a central point for data transmitted over a wireless network by broadcasting signals to any devices with compatible Wi-Fi cards Bluetooth - short-range wireless network technology that is designed to make its own connections between electronic devices - without wires, cables or any direct action from a user Network Service Providers (NSPs) - such as AT&T, backbone links and routers are maintained by NSPs ISP (Internet Service Provider) - operates network devices that handle the physical aspect of transmitting and receiving data from your computer Ping - (Packet Internet Grouper) - sends a signal to a specific Internet address and waits for a reply. Traceroute - records packet's path, including intermediate routers from your computer to its destination Domain name- An easy to remeber name that translates into a computer IP address Top level domain- ex: ".com" ".org" ".edu" .com would imply the host name is owned by a commercial busniess Voiceband modem- Usually refferred to as a modem, converts the digital signals from your computer into signals that can travel through telephone lines. DSL(Digital Subscriber Line)- a high speed, digital, always on internet access technology that uses standard phonelines to transport data ISDN (Integrated Services Digital Network)- connections move data faster that a dial-up connection, but not as fast as DSL or cable modems DOCSIS (Date over cable service interface specification)- a security technology that filters packets to certain ports, including the port the windows operating system uses for network
Bandwidth- a communications channel like your CATV cable carries packets at a constant speed DSS (digital sattellite servcie)- uses a geosynchronous or low-earth sattellite to transmit television, voice, or computer data directly to and from a sattelite dish or base station owned or leased by an individual WAP (Wireless access protocol)- a communications protocol that provides wireless internet access from handheld devices, such as cell phones and pda's Cellular-ready modems- packaged as PC cards that slip easily into the PCMCIA port of a notebook or tablet computer
Slides 1-20
Client/server – contains servers and clients
Peer-to-peer (P2P) – every computer is considered an equal
A network is a collection of computer systems configured to share digital data and resources
LANs extend across limited to geographical area.
Internetwork: collection of autonomous networks
a transmitter encodes the message as a signal
the receiver extracts a signal from the communications channel and converts it back into the form of a message
Messages are encoded as a stream of binary numbers (0s and 1s)
Signals are transmitted as electro-magnetic energy.
CLIENT- system requesting services
SERVER-( system that receives and handles requests from many clients concurrently
LAN (Local Area Network)
WAN (Wide Area Network)
MAN (Metropolitan Area Network)
PAN (Personal Area Network)
Two types of signals:
Analog
Digital
Broadband
multiple signals transmitted on the same channel simultaneously
channel is divided into separate frequency bands, each capable of carrying a signal
Narrowband/baseband
employs [the entirety of its available] bandwidth for one signal
Slides 21-40
Bandwidth
• The bandwidth of a communications channel determines its capacity to transmit data—it’s analogous to the size of plumbing pipes (10MB, 100MB, 1GB, 10GB)
• Analog signals may contain independent waveforms of various frequencies
• The number of frequencies supported by a channel determines its bandwidth
• The bandwidth of a digital channel is usually measured in bits per second (bps)
Sending Information
When you transmit data, it is broken up into small pieces called packets
A packet is a parcel of data that is sent across a network
Has the address of its sender
Has the address of the destination
Has some data
When packets reach their ultimate destination, they are put back together into the data that was originally transmitted
Data can be sent in two ways:
Synchronous protocols
Asynchronous protocols
Packet Switching
ì The message is made of separate data packets, each addressed to the destination ì Packets are transmitted over any available connection to the destination ì The receiving node reassembles the message
Repeaters
boost the signal strength over transmission medium
Bridges
isolate LANs from unnecessary traffic, but connect LANs to neighboring networks
Key words
Communications network- the combination of hardware,software, and connecting links that transport data
Shared resources-hardware,software, and data available to authorized network users
PAN-personal area network and it refers to the interconnection of personal digital devices within a range of 30 feet
MAN-metropolitan area network is a public high-speed network capable of voice and data transmission within a range of about 50 miles
LAN-local area network is a data communications network that typically connects personal computers within a very limited geographical area
WAN-wide area network covers a large geographical area and typically consists of several smaller networks, which might use different computer platforms and network technologies
NAN-neighborhood area network provides connectivity within a limited geographical area, usually spread over several buildings
client/server network-contains one or more computers configured with server software, and other computers configured with client software that access the servers
workstations/client computers-computers running client software
peer-to-peer network- treats every computer as an "equal" so that workstations can store network data
server-a computer that is connected to a network and that serves or distributes resources to network users
host computer- any computer that provides services to network users
modem-network device connected to a computer that converts the digital signals from a computer into signals that can travel over a network
modulation-changing the characteristics of a signal
Demodulation-changes a signal back to its original state
cable modem-type of modem used for TV
Network Interface card-small circuit board that converts the digital signals from a computer into signals that can travel over a network
transceiver- a wireless network sends and recieves data
hub-broadcast data to workstations and peripherals
routers- connect one network to another
repeater-network device that amplifies and regenerates signals so that they can retain the necessary strength to reach their destination
communications channel-physical path or a frequency for a signal transmission
wired network-travels from one device to another through cables
wireless network- travels through the air
Slides 41-57
Protocols
Communications protocol - a set of rules for efficiently transmitting data from one network node to another
Best known protocol: TCP/IP (internet protocol suite) – set of protocols used for the internet
Sending computer: prepares data for transmission
Receiving computer: strips the packets of addressing information; reassembles the data from the packets
TCP/IP is the glue that holds the Internet together
The IP part of TCP/IP defines the format for the addresses that identify computers on the Internet
These addresses are called IP addresses
An IP address is a series of numbers, such as 204.127.129.001
ISPs need static IP addresses
Numbers are hard to remember, so host computers also have names called domain names; a domain names corresponds to an IP address; domain name system
Internet 2- consortium of government, industry, and education
The consortium- establishes network capabilities to support national research
National LambdaRail- High-speed national network running on fiber
Wireless Networks
infrared broadcasting
radio frequency broadcasting
spread spectrum (cell telephony)
direct sequence spread spectrum (DSSS)
frequency hopping spread spectrum (FHSS)
Using “ping” or “traceroute,” one can discover the length of time that data is in transit
On average, data within the US usually arrives at its destination 110-120 milliseconds (ms) after it is sent
Network Monitors
Keep track of network traffic, number of packets, packet size, collisions, re-transmissions, etc.
Enable planning for growth and quality
Network Analyzers
Randomly dissect packets, analyze problems, and determine the source of errors
Portals
Web entry stations that offer quick and easy access to a variety of services
Consumer portals include search engines, e-mail services, chat rooms, references, news headlines, shopping malls, and other servicesCorporate portals on intranets serve the employees of particular corporations
Vertical portals are targeted at members of a particular industry or economic sector
Nets
Intranets, extranets, electronic data interchange (EDI)
Keywords from "Networks" PDF
Protocols - rules that ensure the orderly and accurate transmission and reception of data; start and end transmission, recognize error, sent data at the appropriate speed, and identify the correct senders and recipientsHandshaking - protocols helps help network devices negotiate and establish communications
Packets - the process by which you send a file or an e-mail over a network,the file is actually broken up into small pieces. It is a "parcel" of dad that is sent across a computer network
Packet Switching - the technology of dividing a message into several packets that can be routed or independently to their destination to avoid out-of-service or congested links
Circuit Switching - establishes a dedicated, private link between one telephone and another for the duration of a call; more efficient alternative to circuit switching
TCP/IP (Transmission Control Protocol/Internet Protocol) - breaks messages into packets and addresses them for the transmission over the Internet
HTTP (Hypertext Transfer Protocol) - Exchanges information over the web
FTP (File Transfer Protocol) - Transfers files between local and remote host computers
POP (Post Office Protocol) - Transfers mail from an e-mail server to a client inbox
SMTP (Simple Mail Transfer Protocol) - transfers e-mail messages from client computers to an e-mail server
IMAP (Internet Mail Access Protocol) - an alternative to POP
TELNET (Telecommunications Network) - allows users who are logged on to one host to access another host
SSL (Secure Sockets Layer) - Provides secure data transfer over the Internet
Ethernet - broadcasts data packets to all networks is accepted only by the device to which it is addressed
CSMA/CD Protocol (Carrier Senese Multiple Access with Collision Detection) - takes care of situation in which two network devices attempt to transmit packets at the same time
Uplink Port - simple step up from a basic single-humb network is to connect several hubs
Wi-Fi Network - transmits data as radio waves over predefined frequencies, much like cordless phones.
War Driving/LAN-Jacking - occurs when hackers cruise around with a Wi-Fi equipped notebook computer that is set up to search for Wi-Fi signals coming from home or corporate Wi-Fi networks. War drivers can access and use unsecured Wi-Fi networks
WEP (Wired Equivalent Privacy) - essential step in making Wi-Fi-transmitted data useless to intruders
Wi-Fi card - transmitter, receiver, and antenna to transmit signals
Wireless Access Point - provides a central point for data transmitted over a wireless network by broadcasting signals to any devices with compatible Wi-Fi cards
Bluetooth - short-range wireless network technology that is designed to make its own connections between electronic devices - without wires, cables or any direct action from a user
Network Service Providers (NSPs) - such as AT&T, backbone links and routers are maintained by NSPs
ISP (Internet Service Provider) - operates network devices that handle the physical aspect of transmitting and receiving data from your computer
Ping - (Packet Internet Grouper) - sends a signal to a specific Internet address and waits for a reply.
Traceroute - records packet's path, including intermediate routers from your computer to its destination
Domain name- An easy to remeber name that translates into a computer IP address
Top level domain- ex: ".com" ".org" ".edu" .com would imply the host name is owned by a commercial busniess
Voiceband modem- Usually refferred to as a modem, converts the digital signals from your computer into signals that can travel through telephone lines.
DSL(Digital Subscriber Line)- a high speed, digital, always on internet access technology that uses standard phonelines to transport data
ISDN (Integrated Services Digital Network)- connections move data faster that a dial-up connection, but not as fast as DSL or cable modems
DOCSIS (Date over cable service interface specification)- a security technology that filters packets to certain ports, including the port the windows operating system uses for network
Bandwidth- a communications channel like your CATV cable carries packets at a constant speed
DSS (digital sattellite servcie)- uses a geosynchronous or low-earth sattellite to transmit television, voice, or computer data directly to and from a sattelite dish or base station owned or leased by an individual
WAP (Wireless access protocol)- a communications protocol that provides wireless internet access from handheld devices, such as cell phones and pda's
Cellular-ready modems- packaged as PC cards that slip easily into the PCMCIA port of a notebook or tablet computer
Slides 1-20
LAN (Local Area Network)
- WAN (Wide Area Network)
- MAN (Metropolitan Area Network)
- PAN (Personal Area Network)
Two types of signals:- Analog
- Digital
Broadband- multiple signals transmitted on the same channel simultaneously
- channel is divided into separate frequency bands, each capable of carrying a signal
Narrowband/basebandSlides 21-40
Bandwidth
Sending Information
Data can be sent in two ways:
- Packet Switching
ì The message is made of separate data packets, each addressed to the destinationì Packets are transmitted over any available connection to the destination
ì The receiving node reassembles the message
- Repeaters
- boost the signal strength over transmission medium
- Bridges
- isolate LANs from unnecessary traffic, but connect LANs to neighboring networks
Key wordsCommunications network- the combination of hardware,software, and connecting links that transport data
Shared resources-hardware,software, and data available to authorized network users
PAN-personal area network and it refers to the interconnection of personal digital devices within a range of 30 feet
MAN-metropolitan area network is a public high-speed network capable of voice and data transmission within a range of about 50 miles
LAN-local area network is a data communications network that typically connects personal computers within a very limited geographical area
WAN-wide area network covers a large geographical area and typically consists of several smaller networks, which might use different computer platforms and network technologies
NAN-neighborhood area network provides connectivity within a limited geographical area, usually spread over several buildings
client/server network-contains one or more computers configured with server software, and other computers configured with client software that access the servers
workstations/client computers-computers running client software
peer-to-peer network- treats every computer as an "equal" so that workstations can store network data
server-a computer that is connected to a network and that serves or distributes resources to network users
host computer- any computer that provides services to network users
modem-network device connected to a computer that converts the digital signals from a computer into signals that can travel over a network
modulation-changing the characteristics of a signal
Demodulation-changes a signal back to its original state
cable modem-type of modem used for TV
Network Interface card-small circuit board that converts the digital signals from a computer into signals that can travel over a network
transceiver- a wireless network sends and recieves data
hub-broadcast data to workstations and peripherals
routers- connect one network to another
repeater-network device that amplifies and regenerates signals so that they can retain the necessary strength to reach their destination
communications channel-physical path or a frequency for a signal transmission
wired network-travels from one device to another through cables
wireless network- travels through the air
Slides 41-57
Protocols
Communications protocol - a set of rules for efficiently transmitting data from one network node to another
Best known protocol: TCP/IP (internet protocol suite) – set of protocols used for the internet
Sending computer: prepares data for transmission
Receiving computer: strips the packets of addressing information; reassembles the data from the packets
TCP/IP is the glue that holds the Internet together
- The IP part of TCP/IP defines the format for the addresses that identify computers on the Internet
- These addresses are called IP addresses
- An IP address is a series of numbers, such as 204.127.129.001
- ISPs need static IP addresses
Numbers are hard to remember, so host computers also have names called domain names; a domain names corresponds to an IP address; domain name systemInternet 2- consortium of government, industry, and education
The consortium- establishes network capabilities to support national research
National LambdaRail- High-speed national network running on fiber
Wireless Networks
infrared broadcasting
radio frequency broadcasting
spread spectrum (cell telephony)
direct sequence spread spectrum (DSSS)
frequency hopping spread spectrum (FHSS)
Using “ping” or “traceroute,” one can discover the length of time that data is in transit
On average, data within the US usually arrives at its destination 110-120 milliseconds (ms) after it is sent
Network Monitors
Keep track of network traffic, number of packets, packet size, collisions, re-transmissions, etc.
Enable planning for growth and quality
Network Analyzers
Randomly dissect packets, analyze problems, and determine the source of errors
Portals
Web entry stations that offer quick and easy access to a variety of services
Consumer portals include search engines, e-mail services, chat rooms, references, news headlines, shopping malls, and other servicesCorporate portals on intranets serve the employees of particular corporations
Vertical portals are targeted at members of a particular industry or economic sector
Nets
Intranets, extranets, electronic data interchange (EDI)